Adjustable exercise bicycle

ABSTRACT

An adjustable exercise bicycle includes a fixed frame, a seat, a movable frame, a locking device, a pedal device and an assisting device. The assisting device is arranged between the fixed frame and the movable frame. The assisting device is for forcing the movable frame and generating a first moment about the axis. The total weight of the movable frame and its loading generate a second moment about the axis. The resultant moment of the first moment and the second moment is a third moment which can move the movable frame from a second angle to a first angle when the movable frame is oriented at an unlocked state. The user can force the pedal device against the third moment for moving the movable frame from the first angle to the second angle.

RELATED APPLICATIONS

The application claims priority to Chain Application Serial Number 201310362903, filed Aug. 19, 2013, which is herein incorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to an indoor exercise apparatus. More particularly, the present disclosure relates to an exercise bicycle having an adjustable distance between the pedal device and the seat.

2. Description of Related Art

The exercise bicycle is one of the common indoor exercise apparatus. Many of these exercise bicycles must accommodate users of varying heights and preferences. Often this adjustment is accomplished by adjusting the position of the seat. However, this kind of exercise bicycles often suffers from several undesirable traits.

First, the exercise bicycle should leave a reserved space for adjusting the position of a seat to move closer to or far from a pedal device. The reserved space not only increases the total length of the exercise bicycle, but also raises the manufacturing costs.

Second, the distance between the seat and a console or front handles will be changed when the user adjusts the position of the seat. In other words, the short user will move the seat closer to the pedal device so that the distance between the user and the console or the front handles is shorter; the tall user will move the seat away from the pedal device so that the distance between the user and the console or the front handles is longer. It is inconvenient that the console or the front handles too close or too far from the user to operate or to use. Especially for the tall users who are so far away from the console and the front handles that the screen becomes uncomfortable to view.

In addition, there are some apparatus can adjust the distance between the movable frame and the seat or switch two different exercising types by changing the position of the movable frame without changing the position of the seat. For instance, an apparatus for exercising upper and lower body portions of a user includes a fixed frame, a seat, a movable frame, a locking device and a crank assembly. The seat is arranged on the fixed frame. The movable frame is pivotally coupled to the fixed frame about a pivot axis and can be swung between a first position and a second position. The locking device is for locking the movable frame between the first position and the second position. The crank assembly is arranged on the movable frame. The crank assembly provides upper body exercise when the movable frame is oriented at the first position. The crank assembly provides lower body exercise when the movable frame is oriented at the second position. In use, the user should grab the movable frame in one hand for rotating it to the desired position and operate the locking device by the other hand for locking the movable frame to change the position of the movable frame. It is laborious and inconvenient for the user to carry at least the weight of the movable frame and the crank assembly and need to repeatedly confirm whether the position is appropriate during such an adjusting process.

On the other hand, to adjust the position of the seat, the user must disengage the locking device, allowing the seat to move in one or more degrees of freedom. After the desired position is achieved, the locking device is reengaged to return the seat to a fixed position. Nevertheless, some locking devices suffer from safety hazards as it is possible to unintentionally disengage the locking device while the user is still seated.

Furthermore, the typical locking device has a pin to optionally insert into one of the positioning holes to adjust the position of the seat. This kind of locking device has several merits, like simple structure, low cost, easy operation, etc., but there is still space for improvement. Backlash is typically a result of part clearances needed in the typical locking device. The undesirable backlash would be caused by the clearance between the outer diameter of the pin and the inner diameter of the positioning hole. While this clearance is required for operation, manufacture, and assembly, it causes an undesirable looseness between the seat post and the exercise bicycle. Reducing the clearances between these parts reduces backlash, but at the expense of tighter machine tolerances, which increase the cost of the mechanism

SUMMARY

According to one embodiment of the present invention, an adjustable exercise bicycle includes a fixed frame, a seat, a movable frame, a locking device, a pedal device and an assisting device. The seat is arranged on the fixed frame for providing a user to seat. The movable frame is pivotally coupled to the fixed frame about an axis for being swung between a first angle and a second angle. The locking device is for locking the movable frame at a chosen angle within a swing range of the movable frame. The locking device has a lever arranged within reach on the fixed frame when the user is seating and it is for turning the movable frame from a locked state to an unlocked state. The pedal device is pivotally coupled to the movable frame about a rotating shaft. When the movable frame is oriented at the first angle, the rotating shaft is oriented at a first position. When the movable frame is oriented at the second angle, the rotating shaft is oriented at a second position which is more distant from the seat than the first position. The rotating shaft is swung between the first position and the second position to form a swing track. The assisting device is arranged between the fixed frame and the movable frame. The assisting device is for forcing the movable frame and generating a first moment about the axis. The total weight of the movable frame and its loading generate a second moment about the axis. The resultant moment of the first moment and the second moment is a third moment which can move the movable frame from the second angle to the first angle when the movable frame is oriented at the unlocked state. The user can force the pedal device against the third moment for moving the movable frame from the first angle to the second angle.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which:

FIG. 1 is a perspective view of an adjustable exercise bicycle according to the first embodiment of the present invention;

FIG. 2 is a right side view of FIG. 1;

FIG. 3A is a left side view of FIG. 1 when a movable frame is oriented at a first angle;

FIG. 3B is a left side view of FIG. 1 when the movable frame is oriented at a second angle;

FIG. 4A is a force schematic diagram of FIG. 3A when the movable frame is oriented at the first angle;

FIG. 4B is a force schematic diagram of FIG. 3B when the movable frame is oriented at the second angle;

FIG. 5 is a force schematic diagram of an adjustable exercise bicycle according to the second embodiment of the present invention when a movable frame is oriented at a second angle;

FIG. 6 is a perspective view of an adjustable exercise bicycle according to the third embodiment of the present invention;

FIG. 7 is a side view of FIG. 6 when a movable frame is oriented at a second angle;

FIG. 8 is an enlarged fragmentary view of a locking device of the adjustable exercise bicycle of FIG. 3A;

FIG. 9 is a cross-sectional view of FIG. 8; and

FIG. 10 is a cross-sectional view of a locking device of an adjustable exercise bicycle according to the forth embodiment of the present invention.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically depicted in order to simplify the drawings.

FIG. 1 is a perspective view of an adjustable exercise bicycle according to the first embodiment of the present invention. FIG. 2 is a right side view of FIG. 1. As shown in FIG. 1 and FIG. 2, an adjustable exercise bicycle 100 includes a fixed frame 110, a seat 120, a movable frame 130, a locking device 140, a pedal device 150 and an assisting device 160. The seat 120 is arranged on the fixed frame 110 for seating and the position of the seat 120 is fixed. The present embodiment uses the seat 120 with a backrest 121. The control panel 122 is also arranged on the fixed frame 110 for operating or monitoring various parameters during the exercise. The pedal device 150 is arranged on the movable frame 130. The movable frame 130 is cooperating with the assisting device 160 to have the pedal device 150 be moved related to the fixed frame 110 for adjusting the distance between the pedal device 150 and the seat 120. A user can adjust the pedal device 150 to the proper position according to the user's height and preferences. Besides, the distance between the seat 120 and the control panel 122 or the front handles 123 is fixed due to the position of the seat 120 is fixed. In other words, the distance between the seat 120 and the control panel 122 or the front handles 123 won't change no matter how the user adjusts the pedal device 150. In this way, the problem of tall users being so far away from the console panel 122 and the front handles 123 that the screen becomes uncomfortable to view or to operate can be solved.

FIG. 3A is a left side view of FIG. 1 when a movable frame 130 is oriented at a first angle. FIG. 3B is a left side view of FIG. 1 when the movable frame 130 is oriented at a second angle. Referring to FIG. 1 to FIG. 3B, the movable frame 130 is pivotally coupled to the fixed frame 110 about an axis 131 for being swung between a first angle shown as FIG. 3A and a second angle shown as FIG. 3B. The axis 131 is oriented at the bottom of the fixed frame 110. The movable frame 130 is close to the seat 120 when it is at the first angle and the movable frame 130 is far from the seat 120 when it is at the second angle.

The locking device 140 is for locking the movable frame 130 at a chosen angle within a swing range of the movable frame 130. The angle between the first angle and the second angle (the swing range) is about sixty degrees in the present embodiment. The locking device 140 can lock the movable frame 130 at fifteen different chosen angles including the first angle and the second angle. Specifically, within the swing range, every four degrees is a chosen angle and there are fifteen chosen angles can be chosen including the first angle and the second angle. The concrete structure of the locking device 140 of the present embodiment will be illustrated and described in more detail later on and there is only a brief description herein.

The locking device 140 has a lever 141 arranged on the fixed frame 110. The lever 141 is for turning the movable frame 130 from a locked state to an unlocked state. In particular, the lever 141 is oriented within reach on the fixed frame 110 when the user is seated. For example, the lever 141 is oriented below the seat 120. This design is intended to allow the user to operate the lever 141 for the following adjustment without leaving the seat 120. Therefore, the position of the lever 141, such as being oriented in front of the seat 120 on the fixed frame 110 or being oriented at lateral sides of the seat 120, as long as the user can operate the lever 141 without leaving the seat 120, all those positions will not depart from the spirit of designing the lever's position of the present embodiment.

The pedal device 150 is pivotally coupled to the movable frame 130 and is for providing feet exercise. The pedal device 150 includes a rotating shaft 151 and two pedals 152. The rotating shaft 151 is pivotally coupled to the movable frame 130 and its position is higher than the position of the axis 131. Two pedals 152 are pivotally coupled to two ends of the rotating shaft 151 respectively via two cranks. The pedal device 150 is coupled to a resistance device 170 having a flywheel 171 and a magnetic resistance set 172. The flywheel 171 provides the rotary inertia and the magnetic resistance set 172 is for adjusting the resistance during the rotation of the flywheel 171. The relationship between the pedal device 150 and the resistance device 170 has no direct connection to the main feature of the present embodiment. For this reason, there is only a brief description herein.

FIG. 4A is a force schematic diagram of FIG. 3A when the movable frame 130 is oriented at the first angle. FIG. 4B is a force schematic diagram of FIG. 3B when the movable frame 130 is oriented at the second angle. Referring to FIG. 1 to FIG. 4B, the pedal device 150 is arranged on the movable frame 130 so that the pedal device 150 will change its position with the movable frame 130. When the movable frame 130 is oriented at the first angle, the rotating shaft 151 is oriented at a first position as shown in FIG. 4A. When the movable frame 130 is oriented at the second angle, the rotating shaft 151 is oriented at a second position as shown in FIG. 4B. The distance D₁ between the first position and the seat 120 is shorter than the distance D₂ between the second position and the seat 120. In other words, the first position is closer to the seat 120 than the second position is. The rotating shaft 151 is swung between the first position and the second position to form a swing track T.

The total weight of the movable frame 130 and its loading includes the weight of the movable frame 130, the weight of the pedal device 150 and the weight of any object which is arranged on the movable frame 130, like the resistance device 170. The position of the center of gravity C of the total weight won't exceed a vertical line L which is passing through the axis 131 in the lateral view as shown in FIG. 4A or FIG. 4B. In other words, the position of the center of gravity C is oriented in front of the vertical line L despite the position of the movable frame 130 between the first angle and the second angle. That is, the position of the center of gravity C is always oriented at the left side of the vertical line L and also won't oriented on the vertical line L in FIG. 4A and FIG. 4B.

The assisting device 160 is arranged between the fixed frame 110 and the movable frame 130 and is for assisting the user to adjust the position of the movable frame 130 related to the fixed frame 110. The assisting device 160 is a gas spring and other object like a torsion spring which has buffer or reset function can be used as an alternative. Two ends of the assisting device 160 are pivotally coupled to the fixed frame 110 and the movable frame 130 respectively. The assisting device 160 applies a force F₁ to the movable frame 130 and generates a first moment M₁ about the axis 131. The first moment M₁ which is clockwise in FIG. 4A and FIG. 4B (hereinafter referred as an asymptotic rotation) makes the movable frame 130 move close to the seat 120.

Additionally, the total weight of the movable frame 130 and its loading generate a second moment M₂ about the axis 131. The second moment M₂ which is anticlockwise in FIG. 4A and FIG. 4B (hereinafter referred as a distanced rotation) makes the movable frame 130 move far from the seat 120. The rotating directions of the first moment M₁ and the second moment M₂ are contrary and the resultant moment of the first moment M₁ and the second moment M₂ is a third moment M₃. As a result of the magnitude of the second moment M₂ is slightly less than the magnitude of the first moment M₁, the third moment M₃ has the same rotating direction (the asymptotic rotation) with the first moment M₁.

Specifically, without forcing by any other forces, the movable frame 130 is swung from the second angle to the first angle by the third moment M₃, i.e. the movable frame 130 will be moved close to the seat 120 when the user presses the lever 141 to let the movable frame 130 be oriented at the unlocked state. On the other hands, if the user wants to increase the distance between the seat 120 and the pedal device 150, the user just seats on the seat 120 and applies a force F₃ to the pedals 152 by feet so that the force F₃ will generate a fourth moment M₄ (the distanced rotation) about the axis 131. The movable frame 130 will be moved away from the seat 120. Because the second moment M₂ is slightly less than the magnitude of the first moment M₁, the third moment M₃ can be easily overcome by the fourth moment M₄. Therefore, the movable frame 130 will be swung from the first angle to the second angle to leave away from the seat 120. When the movable frame 130 is swung to the proper position, the user can operate the lever 141 to fix the position of the movable frame 130 on the fixed frame 110. The user doesn't need to force the movable frame 130 for adjusting unless the user wants to increase the distance between the pedal device 150 and the seat 120. If the user wants to decrease the distance between the pedal device 150 and the seat 120, the user only has to operate the lever 141 but doesn't need to operate or to force the movable frame 130. In this configuration, the user can adjust the pedal device 150 to the proper position without leaving the seat 120. It is not only very convenient and effort-saving, but also very easy to use for the user.

It is worthy to note that the magnitude of the first moment M₁ and the second moment M₂ are varying with the position of the movable frame 130. In details, the magnitude of the moment is decided by the magnitude of the force and the moment arm. Either changing the magnitude of the force or the moment arm can change the magnitude of the moment. First, the first moment M₁ is decided by the force F₁ and the vertical distance between the force F₁ and the axis 131 (moment arm.) The assisting device 160 is a gas spring in the present embodiment, the force F₁ provided by the gas spring is varying with the position of the movable frame 130 and so dose the vertical distance between the force F₁ and the axis 131. Hence, the magnitude of the first moment M₁ may remain unchanged or varying with the position of the movable frame 130. On the other hand, the second moment M₂ is decided by the total weight F₂ and the vertical distance between the total weight F₂ and the axis 131 (moment arm.) The total weight F₂ remains unchanged but the vertical distance between the total weight F₂ and the axis 131 will increase or decrease with the movement of the movable frame 130. According to the orientation of FIG. 4A and FIG. 4B, the vertical distance between the total weight F₂ and the axis 131 is shorter when the movable frame 130 is at the first angle, and the vertical distance between the total weight F₂ and the axis 131 is longer when the movable frame 130 is at the second angle. Although the total weight F₂ remains unchanged, the second moment M₂ will gradually increase with the movement of the movable frame 130 from the first angle to the second angle due to the vertical distance between the total weight F₂ and the axis 131 is varying. In short, the magnitude of the second moment M₂ will gradually increase when the movable frame 130 moves away from the seat 120. However, either the first moment M₁ or the second moment M₂ remains unchanged or varies with the position of the movable frame 130, the magnitude of the second moment M₂ is always slightly less than the magnitude of the first moment M₁ during the movement of the movable frame 130. Therefore, the resultant moment (the third moment M₃) can force the movable frame 130 to move closer to the seat 120 when the movable frame 130 is oriented at the unlocked state.

In practice, the foregoing discussions are based on: the position of the center of gravity C is oriented in front of the vertical line L and also won't oriented on the vertical line L despite the position of the movable frame 130 between the first angle and the second angle. That is, the second moment M₂ provided by the total weight F₂ is always the distanced rotation. However, the center of gravity C may be designed to be oriented behind the vertical line L (i.e. the right side of the vertical line L in FIG. 4A or FIG. 4B) or be oriented right on the vertical line L when the movable frame 130 is oriented at the first angle in other embodiment. In this situation, the relationships among those forces are slightly different from the foregoing discussions.

FIG. 5 is a force schematic diagram of an adjustable exercise bicycle according to the second embodiment of the present invention when a movable frame is oriented at a second angle. Basically, the theory of the present embodiment is the same with the foregoing embodiment when the center of gravity C′ is oriented in front of the vertical line L′. The main difference between the present embodiment and the foregoing embodiment is that the center of gravity C′ of the present embodiment can cross the vertical line L′. When the center of gravity C′ is oriented behind the vertical line L′, a force F₁′ will generate a first moment M₁′ about an axis 131′, and a total weight F₂′ of the movable frame 130′ and its loading will generate a second moment M₂′ about the axis 131′. The first moment M₁′ and the second moment M₂′ are both the asymptotic rotation. That is, the first moment M₁′ and the second moment M₂′ can both force the movable frame 130′ to move close to the seat 120′. This kind of situation is different from the first moment M₁ which has contrary rotating direction to the second moment M₂ when the center of gravity C′ is oriented in front of the vertical line L′. The resultant moment of the first moment M₁′ and the second moment M₂′ is a third moment M₃′ which is the asymptotic rotation. To increase the distance between the seat 120′ and the pedal device 150′, the user has to apply a force F₃′ which is larger than the force F₃ for generating a larger fourth moment M₄′ to overcome the third moment M₃′ to move the movable frame 130′ from the first angle which is close to the seat 120′ to the second angle which is far from the seat 120′. On the other hand, the total weight F₂′ cannot generate the second moment M₂′ about the axis 131′ when the center of gravity C is oriented right on the vertical line L′. There is only the force F₁′ which is provided by the assisting device 160′ applying on the movable frame 130′. The force F₁′ generates the first moment M₁′ (the asymptotic rotation) about the axis 131′. If the user wants to increase the distance between the seat 120′ and pedal device 150′, the user has to provide a force for overcoming the first moment M₁′ to move the movable frame 130′ from the first angle which is close to the seat 120′ to the second angle which is far from the seat 120′. The magnitude of the force herein is between the magnitude of the force F₃′ and the magnitude of the force F₃ of the first embodiment. General speaking, the vertical line L′ is a critical line for the center of gravity C′. When the center of gravity C′ is behind the vertical line L′, the farther is the vertical distance between the center of gravity C′ and the vertical line L′, the larger is the magnitude of the force which is provided by the user to move the movable frame 130′ away from the seat 120′. Overall, the user merely has to apply larger force on the movable frame 130′ to move it away from the seat 120′ whether the center of gravity C′ is behind or is oriented right on the vertical line L′, the rest functions of the second embodiment are the same with the first embodiment.

FIG. 6 is a perspective view of an adjustable exercise bicycle according to the third embodiment of the present invention. FIG. 7 is a side view of FIG. 6 when a movable frame is oriented at a second angle. The principles of an adjustable exercise bicycle 200 of the present embodiment are substantially the same with the adjustable exercise bicycle 100 of the first embodiment. The adjustable exercise bicycle 200 includes a fixed frame 210, a seat 220, a movable frame 230, a locking device 240, a pedal device 250 and an assisting device 260. The seat 220 is arranged on the fixed frame 210. The movable frame 230 is pivotally coupled to the fixed frame 210 about an axis 231. The difference between the axis 131 and the axis 231 is that the axis 231 is oriented at the top of the fixed frame 210. The movable frame 230 can be swung related to the fixed frame 210 between a first angle and a second angle. Similarly, the movable frame 230 is close to the seat 220 when it is oriented at the first angle and the movable frame 230 is far from the seat 220 when it is oriented at the second angle.

The locking device 240 is for locking the movable frame 230 on the fixed frame 210 between the first angle and the second angle. The locking device 240 includes a positioning frame 241, a pin 242, a lever 243, a cable (not shown) and a spring (not shown.) The positioning frame 241 is curved and arranged on the fixed frame 210 along the direction of the movement of the movable frame 230. The positioning frame 241 has several positioning holes 244 which are equidistant. The pin 242 is arranged on the movable frame 230 and can insert into one of the positioning holes 244 for fixing the related position between the movable frame 230 and the fixed frame 210. The lever 243 is arranged within reach on the fixed frame 210 when the user is seated and is for turning the movable frame 230 from a locked state to an unlocked state. The lever 243 is arranged in front of the seat 220. The cable is coupled to the lever 243 and the pin 242. The pin 242 will be pulled out of the positioning hole 244 when the user presses the lever 243. Conversely, the pin 242 is pushed by the spring to insert into the closest positioning hole 244 when the user releases the lever 243 and slightly moves the movable frame 230 for fixing the related position between the movable frame 230 and the fixed frame 210 again. Other technologies to the present invention, a person has ordinary skill in the art to the field of locking device should complete it without undue experimentations, so that the details are not narrated herein.

The pedal device 250 includes a rotating shaft 251 and two pedals 252. The rotating shaft 251 is pivotally coupled to the movable frame 230 and its position is lower than the position of the axis 231. When the movable frame 230 is oriented at the first angle, the rotating shaft 251 is oriented at a first position. When the movable frame 230 is oriented at the second angle, the rotating shaft 251 is oriented at a second position. The distance between the first position and the seat 220 is shorter than the distance between the second position and the seat 220. In other words, the first position is close to the seat 220 and the second position is far from the seat 220. Furthermore, the pedal device 250 of the present embodiment is coupled to a resistance device 270 which has a flywheel and a magnetic resistance set. The flywheel provides the rotary inertia and the magnetic resistance set is for adjusting the resistance during the rotation of the flywheel. The concrete structure and relationship between the pedal device 250 and the resistance device 270 are substantially the same with the foregoing embodiments, so there is only a brief description herein.

The total weight of the movable frame 230 and its loading includes the weight of the movable frame 230, the weight of the pedal device 250 and the weight of any object which is arranged on the movable frame 230, like the resistance device 270. The position of the center of gravity C″ of the total weight won't exceed a vertical line L″ which is passing through the axis 231 in the lateral view as shown in FIG. 7. In other words, the position of the center of gravity C″ is oriented in front of the vertical line L″ despite the position of the movable frame 230 between the first angle and the second angle. That is, the total weight of the movable frame 230 and its loading generate a second moment about the axis 231. The second moment is always the asymptotic rotation.

The assisting device 260 is arranged between the fixed frame 210 and the movable frame 230 and is for assisting the user to adjust the position of the movable frame 230 related to the fixed frame 210. The assisting device 260 applies a force to the movable frame 230 and generates a first moment about the axis 231. The first moment is the distanced rotation which makes the movable frame 230 move away from the seat 220.

In addition, the total weight of the movable frame 230 and its loading generate the second moment about the axis 231. The second moment makes the movable frame 230 move close to the seat 220 when the movable frame 230 is oriented at the unlocked state. The rotating directions of the first moment and the second moment are contrary and the resultant moment of the first moment and the second moment is a third moment. As a result of the magnitude of the first moment is slightly less than the magnitude of the second moment, the third moment is the asymptotic rotation the same with the second moment.

More particularly, without forcing by any other force, the movable frame 230 is swung from the second angle which is far from the seat 220 to the first angle which is close to the seat 220 by the third moment when the user presses the lever 243 to let the movable frame 230 be oriented at the unlocked state. On the other hands, if the user wants to increase the distance between the seat 220 and the pedal device 250, the user just seats on the seat 220 and applies a force to the pedals 252 by feet so that the force will generate a fourth moment (the distanced rotation) about the axis 231. The movable frame 130 will be moved away from the seat 220. The third moment of the present embodiment is the same with the third moment M₃ which can be easily overcame by the fourth moment so that the movable frame 230 can be swung from the first angle which is close to the seat 220 to the second angle which is far from the seat 220.

According to the aforementioned embodiments, the adjustable exercise bicycle of the present invention sets the adjustable object on the pedal device but not on the seat so that the total length of the exercise bicycle will be decreased and also can lower the manufacturing cost of the exercise bicycle. The fixed seat is safer than the adjustable seat. The fixed seat can avoid the safety hazards as it is possible to unintentionally disengage the locking device while the user is still seated and also solves the problem of the tall users are so far away from the console and the front handles that the screen becomes uncomfortable to operate or to view. Because of the designs of the movable frame and the assisting device, the user can adjust the distance between the pedal device and the seat without leaving the seat. More conveniently, the user doesn't need to force the movable frame for adjusting unless the user wants to increase the distance between the pedal device and the seat. If the user wants to decrease the distance between the pedal device and the seat, the user only has to operate the lever but doesn't need to operate or force the movable frame. It is very convenient and effort-saving.

Back to the adjustable exercise bicycle 100 of the first embodiment, referring FIG. 4B, the dot portion in FIG. 4B is the schematic diagram of the movable frame 130 oriented at the first angle. The second position is at the lower front of the first position. The swing track T of the rotating shaft 151 is upper right to lower left according to the orientation of the FIG. 4B for taking into account the ergonomics and the operational comfort of the user. The user needs to apply the force on the movable frame 130 when the user wants to move the movable frame 130 from the first angle to the second angle. For the seated user, the most comfortable direction for feet to extend and apply force on the movable frame 130 is from back to front and from top to bottom. In order to make sure that the user's feet extend and apply force like the foregoing direction in the whole adjusting process, the present embodiment has the following design: The top center of the seat 120 and the rotating shaft 151 are in a straight line. There is a changing angle between the straight line and the horizontal plane. The changing angle will be changed with the movable frame 130 being moved from the first angle to the second angle. The variation of the changing angle won't exceed fifteen degrees when the movable frame 130 is swung between the first angle and the second angle. Specifically, the top center of the seat 120 and the rotating shaft 151 which is oriented at the first position are in a straight line X₁. The top center of the seat 120 and its tangent to the swing track T are in a straight line X₂. The changing angle θ between the straight line X₁ and the straight line X₂ is the largest changing angle which won't exceed fifteen degrees during the movement of the movable frame 130 from the first angle to the second angle. The straight line is upper back to lower front in the whole adjusting process. Hence, the ergonomics won't vary from the adjusting process of the movable frame 130 and the operational comfort will remain the same even for different users.

In particular, there are other embodiments can achieve the forgoing effect as the first embodiment. For example, set the position of the axis higher than the position of the swing track and also let the first position which is near the seat is higher than the second position which is far from the seat. Therefore, the seated user can apply the force from upper back to lower front which is the most comfortable direction for the feet extension. In short, the swing track of this example has the same beneficial effects as the swing track T of the first embodiment.

Besides, the user's posture while using the pedal device and the distance between the user and the pedal device have been specially designed to meet the ergonomic design and many limitations of the mechanism design. In other words, the designer not only has to consider the ergonomics and the operational comfort of the user during the adjusting process, like the height and the positional relationship of the swing track T in the first embodiment, but also has to pay attention to space utilization, the height of the pedal device from the ground (to avoid the pedals hitting the ground while using) and other mechanism design factors. Under the circumstance of the swing track is roughly the same height from the ground and the positional relationship between the swing track and the user is broadly unchanged, setting the axis below the swing track, as the first embodiment, is a better practice of more space-saving, having lower center of gravity and high stability.

FIG. 8 is an enlarged fragmentary view of a locking device of the adjustable exercise bicycle of FIG. 3A. FIG. 9 is a cross-sectional view of FIG. 8. Please refer to FIG. 3A, FIG. 8 and FIG. 9. In order to solve the stability problem of the adjustable seat, the present embodiment not only sets the adjustable object on the pedal device 150, but also improves the locking device 140 which is for fixing the related position between the movable frame 130 and the fixed frame 110. The movable frame 130 can be firmly locked on the fixed frame 110 and can avoid the damage of the undesirable looseness when the movable frame 130 is oriented at the locked state. The locking device 140 includes a positioning frame 142, a restricted frame 143, a linkage member 144, two elastic member 145, a first pin 146 and a second pin 147.

The positioning frame 142 is curved along a first direction T₁ and is arranged on the fixed frame 110. The positioning frame 142 has sixteen positioning holes which are arranged along the first direction. Each positioning hole has a first hole wall and a second hole wall. In FIG. 8, a first positioning hole 1421 has a first hole wall 1421 a and a second hole wall 1421 b, and a second positioning hole 1422 has a first hole wall 1422 a and a second hole wall 1422 b. The first hole wall 1421 a, 1422 a and the second hole wall 1422 a, 1422 b are respectively oriented on two sides of the first positioning hole 1421 and the second positioning hole 1422 corresponding to two ends of the first direction T₁.

The restricted frame 143 is arranged on the movable frame 130 and can be swung between the first angle and the second angle along the first direction T₁. The restricted frame 143 is a rectangular frame having two upper openings 148 and two lower openings 149. Two sides of each lower opening 149 are a first resisting portion 149 a and a second resisting portion 149 b corresponding to the two ends of the first direction T₁.

The linkage member 144 is arranged inside the rectangular restricted frame 143. The linkage member 144 can be moved between a locked position which is near the positioning frame 142 and an unlocked position which is far from the positioning frame 142 along a second direction T₂. The second direction T₂ is perpendicular to the tangential direction of the first direction T₁. Furthermore, the lever 141 can move the linkage member 144 from the locked position to the unlocked position. In other words, the linkage member 144 is oriented at the locked position when the movable frame 130 is oriented at the locked state, and the linkage member 144 is oriented at the unlocked position when the movable frame 130 is oriented at the unlocked state.

The two elastic members 145 are coupled between the restricted frame 143 and the linkage member 144 and are pushing the linkage member 144 toward the positioning frame 142 along the second direction T₂. In brief, the elastic members 145 are both compression springs. The elastic members 145 will push the linkage member 144 toward the locked position without any other force. In use, the lever 141 is coupled to the linkage member 144 via the cable 1411. The cable 1411 will force the linkage member 144 down along the second direction T₂ to pressure the elastic members 145 and then move to the unlocked position. If the user releases the lever 141, the elastic members 145 will push the linkage member 144 toward the locked position along the second direction T₂. It should be noted that the purpose of using the elastic members 145 is for pushing the linkage member 144 toward the locked position when the linkage member 144 is moved to the unlocked position. Therefore, the number of the elastic members 145 is not limited in two. With the proper adjustment of the position of the elastic member, using only one elastic member can achieve the same efficacy with using two elastic members.

The first pin 146 and the second pin 147 are pivotally coupled to the linkage member 144. The first pin 146 and the second pin 147 both pass through the restricted frame 143 and respectively insert into the corresponding upper openings 148 and the lower openings 149. The first pin 146 has a first guiding plane 146 a and a first pressed portion 146 b. The second pin 147 has a first guiding plane 147 a and a first pressed portion 147 b.

The first guiding plane 146 a is oriented at one end of the first pin 146 which is near the positioning frame 142 and the second guiding plane 147 a is oriented at one end of the second pin 147 which is near the positioning frame 142. The first guiding plane 146 a and the second guiding plane 147 a are not parallel nor perpendicular to the second direction T₂. Besides, the first guiding plane 146 a and the second guiding plane 147 a of the present embodiment are beveled and both has an angle with the second direction T₂. Specially, the second guiding plane 147 a is face to or opposite to the first guiding plane 146 a. It can be said that the sign of the slopes of the first guiding plane 146 a and the second guiding plane 147 a are different. The first guiding plane 146 a is opposite to the second guiding plane 147 a in the present embodiment. There is a minor image relationship between the first guiding plane 146 a and the second guiding plane 147 a about an axis A. Despite the sign of the slopes of the first guiding plane 146 a and the second guiding plane 147 a are different, their absolute value are the same. Moreover, there are more detail description about the first guiding plane 146 a is face to the second guiding plane 147 a in the following fourth embodiment.

Back to the present embodiment, the first pressed portion 146 b is farther from the positioning frame 142 than the first guiding plane 146 a, and the second pressed portion 147 b is also farther from the positioning frame 142 than the second guiding plane 147 a. The first pressed portion 146 b is oriented at the outer side of the other end of the first pin 146 and the second pressed portion 147 b is oriented at the outer side of the other end of the second pin 147.

The first guiding plane 146 a will touch the first hole wall 1421 a of the first positioning hole 1421 and the second guiding plane 147 a will touch the second hole wall 1422 b of the second positioning hole 1422 when the first pin 146 and the second pin 147 are moved by the linkage member 144 from the bottom up into the positioning hole 1421. As the inserting process of the first pin 146 and the second pin 147, the first guiding plane 146 a is forced and guided by the first hole wall 1421 a so that the first pin 146 will rotate clockwise and the second guiding plane 147 a is forced and guided by the second hole wall 1422 b so that the second pin 147 will rotate anticlockwise. The first pressed portion 146 b will be stopped by the first resisting portion 149 a when the first pin 146 rotates slightly and the second pressed portion 147 b will be stopped by the second resisting portion 149 b when the second pin 147 rotates slightly. While the linkage member 144 is oriented at the locked position, the first guiding plane 146 a engages with the first hole wall 1421 a of the first positioning hole 1421 at a first engaged position E₁, the first pressed portion 146 b engages with the first resisting portion 149 a of the restricted frame 143 at a second engaged position E₂, the second guiding plane 147 a engages with the second hole wall 1422 b of the second positioning hole 1422 at a third engaged position E₃ and the second pressed portion 147 b engages with the second resisting portion 149 b of the restricted frame 143 at a fourth engaged position E₄. The first engaged position E_(l) and the second engaged position E₂ are oriented at the outer side of the first pin 146 for restricting the leftward displacement of the first pin 146. The third engaged position E₃ and the fourth engaged position E₄ are oriented at the outer side of the second pin 147 for restricting the rightward displacement of the second pin 147. Hence, the movable frame 130 cannot be moved along the first direction T₁ and can be locked firmly on the fixed frame 110.

It should be noted that the movable frame 130 will have a smaller minimum adjusting angle, if the first pin 146 and the second pin 147 insert into the first positioning hole 1421 and the second positioning hole 1422 respectively. More specifically, the movable frame 130 can be moved only four degrees to reach the next chosen angle when the first pin 146 and the second pin 147 are pulled out of the first positioning hole 1421 and the second positioning hole 1422 respectively. That is, the minimum adjusting angle of the movable frame 130 is four degrees. In this way, the movable frame 130 can be locked at fifteen different chosen angles and there are fifteen different distances between the pedal device 150 and the seat 120 for different users. However, the first positioning hole 1421 and the second positioning hole 1422 can be combined together as a larger positioning hole for inserting by both the first pin 146 and the second pin 147 in other embodiment. The larger positioning hole also has a first hole wall which engages with the first guiding plane 146 a of the first pin 146 and a second hole wall which engages with the second guiding plane 147 a of the second pin 147. Although the amount of the chosen angle of the present embodiment which has the larger positioning hole is smaller than the first embodiment, the minimum adjusting angle of the movable frame 130 of the present embodiment is larger than the first embodiment so that the user can adjust greater distance between the pedal device 150 and the seat 120 each time. In addition, the second engaged position E₂ and the fourth engaged position E₄ not only can be oriented below the pivot shaft 144 a but also can be oriented above the pivot shaft 144 a according to the orientation of FIG. 8. In other words, the first pressed portion 146 b can engage with the first resisting portion 148 a of the upper opening 148 and the second pressed portion 147 b can engage with the second resisting portion 148 b of the upper opening 148 to have a new second engaged position and a new fourth engaged position. Therefore, the first pressed portion 146 b and the second pressed portion 147 b are not invariable portions of the first pin 146 and the second pin 147 but merely refer to somewhere of first pin 146 and the second pin 147 pressed by the restrict frame 143. Overall, the first pin 146 and the second pin 147 engage with the first positioning hole 1421, the second positioning hole 1422 and the restrict frame 143 at four engaged positions. The spirit of the locking device 140 is that the four engaged positions restrict the displacement of the first pin 146 and the second pin 147 on the first direction T₁.

FIG. 10 is a cross-sectional view of a locking device of an adjustable exercise bicycle according to the forth embodiment of the present invention. The present embodiment is substantially the same with the foregoing embodiments. The main different between the present embodiment and the foregoing embodiments is that the first guiding plane 146 a′ is face to the second guiding plane 147 a′ in the present embodiment. In this way, the first guiding plane 146 a′ will touch the first hole wall 1421 a′ of the first positioning hole 1421′ and the second guiding plane 147 a′ will touch the second hole wall 1422 b′ of the second positioning hole 1422′ when the first pin 146′ and the second pin 147′ are moved by the linkage member 144′ from the bottom up into the positioning hole 1421′. As the inserting process of the first pin 146′ and the second pin 147′, the first guiding plane 146 a′ is forced and guided by the first hole wall 1421 a′ so that the first pin 146′ will rotate anticlockwise and the second guiding plane 147 a′ is forced and guided by the second hole wall 1422 b′ so that the second pin 147′ will rotate clockwise. The first pressed portion 146 b′ will be stopped by the first resisting portion 149 a′ when the first pin 146′ rotates slightly and the second pressed portion 147 b′ will be stopped by the second resisting portion 149 b′ when the second pin 147′ rotates slightly. While the linkage member 144′ is oriented at the locked position, the first guiding plane 146 a′ engages with the first hole wall 1421 a′ of the first positioning hole 1421′ at a first engaged position E_(l)', the first pressed portion 146 b′ engages with the first resisting portion 149 a′ of the restricted frame 143′ at a second engaged position E₂′, the second guiding plane 147 a′ engages with the second hole wall 1422 b′ of the second positioning hole 1422′ at a third engaged position E₃′ and the second pressed portion 147 b′ engages with the second resisting portion 149 b of the restricted frame 143′ at a fourth engaged position E₄′. In particular, the first engaged position E_(l)' and the second engaged position E₂′ are oriented at the inner side of the first pin 146′ and the third engaged position E₃ and the fourth engaged position E₄ are oriented at the inner side of the second pin 147 in the present embodiment. Besides, other effects of the present embodiment are the same as the foregoing embodiments.

According to the aforementioned embodiments, under the circumstance that the reserved clearances are required for operation, manufacture and assembly, the locking device of the present invention prevents the undesirable collision and vibration between the components of the locking device by the design of the four engaged positions. The locking device of the present invention further improves the stability and the service life of its components without raising the cost or reducing the clearances.

It is worthy to note that, with the changes and the combinations of the components of the locking device, the locking device of the present invention not only can be applied in the exercise bicycle, but also can be applied in other exercise equipments which need to lock the relative position between two frames firmly. For example, adjustable seats of various exercise equipments. The specific examples of the changes and the combinations of the components of the locking device, such as the first direction is not restricted to be curved. The first direction varies from different way that the movable frame is swung related to the fixed frame. For instance, the movable frame is swung related to the fixed frame so that the first direction is curved. If the movable frame is moved horizontally related to the fixed frame, the first direction is horizontal. Furthermore, the restrict frame is not limited as a rectangular frame and is not necessarily to have an opening. The restrict frame can be designed as a long plate as the positioning frame. The long plate has a notch which can contain the first pin and the second pin. The related two sides of the inner side of the notch are the first resisting portion and the second resisting portion respectively. The first pressed portion and the second pressed portion can engage with the first resisting portion and the second resisting portion respectively when the linkage member is oriented at the locked position. Therefore, the restrict frame which is the long plate with the notch can achieve the efficacy of locking the movable frame on the fixed frame firmly. In addition, whether the absolute values of the first guiding plane and the second guiding plane are the same, the first guiding plane and the second guiding plane are beveled or even have curved surfaces, as long as the first guiding plane and the second guiding plane can engage with the first hole wall and the second hole wall respectively and they are face to or opposite to each other, the main proper of the locking device of the present invention will remain unchanged.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. 

What is claimed is:
 1. An adjustable exercise bicycle, comprising: a fixed frame; a seat arranged on the fixed frame; a movable frame pivotally coupled to the fixed frame about an axis for being swung between a first angle and a second angle; a locking device located between the movable frame and the fixed frame for locking the movable frame at a chosen angle between the first angle and the second angle, the locking device having a control member arranged within reach of a user on the seat, the control member controlling the movable frame between a locked state and an unlocked state; a pedal device pivotally coupled to the movable frame via a rotating shaft, the rotating shaft being at a first position when the movable frame is oriented at the first angle and at a second position when the movable frame is oriented at the second angle, the second position being more distant from the seat than the first position; and an assisting device arranged between the fixed frame and the movable frame, the assisting device generating a first moment about the axis; wherein a second moment about the axis is generated from the movable frame and the resultant moment of the first moment and the second moment is a third moment , the third moment being configured to be able to move the movable frame from the second angle toward the first angle when the movable frame is at the unlocked state.
 2. The adjustable exercise bicycle of claim 1, wherein the second position is at the lower front of the first position.
 3. The adjustable exercise bicycle of claim 2, wherein the top center of the seat and the rotating shaft define a straight line, the variation of an angle between the straight line and the horizontal plane being less than fifteen degrees in the lateral view when the movable frame is swung between the first angle and the second angle.
 4. The adjustable exercise bicycle of claim 2, wherein the rotating shaft is swung between the first position and the second position to form a swing track, the axis being located below the swing track.
 5. The adjustable exercise bicycle of claim 1, wherein the rotating shaft is swung between the first position and the second position to form a swing track, the axis being located below the swing track.
 6. The adjustable exercise bicycle of claim 5, wherein the direction of the second moment is the same as the direction of the first moment when the rotating shaft is oriented at the first position.
 7. The adjustable exercise bicycle of claim 5, wherein the direction of the second moment is opposite to the direction of the first moment when the rotating shaft is oriented at the second position.
 8. The adjustable exercise bicycle of claim 1, wherein the rotating shaft is swung between the first position and the second position to form a swing track, the position of the axis being higher than the position of the swing track.
 9. The adjustable exercise bicycle of claim 1, wherein the assisting device is a gas spring having two ends which are pivotally coupled to the fixed frame and the movable frame respectively.
 10. The adjustable exercise bicycle of claim 1, the locking device further comprising: a positioning frame arranged on the fixed frame and having several positioning holes which are arranged along a first direction, each positioning hole having a first hole wall and a second hole wall; a restricted frame arranged on the movable frame and configured to be swung between the first angle and the second angle along the first direction, the restricted frame having a first resisting portion and a second resisting portion; a linkage member selectively moveable between a locked position which is near the positioning frame and an unlocked position which is far from the positioning frame along a second direction, the control member being configured to move the linkage member from the locked position to the unlocked position; at least one elastic member coupled between the restricted frame and the linkage member and pushing the linkage member toward the positioning frame; a first pin pivotally coupled to the linkage member and comprising: a first guiding plane oriented at one end of the first pin which is near the positioning frame and being not parallel nor perpendicular to the second direction, the first guiding plane engaging with the first hole wall of the positioning hole when the linkage member is oriented at the locked position; and a first pressed portion being far from the positioning frame than the first guiding plane, the first pressed portion engaging with the first resisting portion when the linkage member is oriented at the locked position; and a second pin pivotally coupled to the linkage member and comprising: a second guiding plane oriented at one end of the second pin which is near the positioning frame and being not parallel nor perpendicular to the second direction, the second guiding plane engaging with the second hole wall of the positioning hole when the linkage member is oriented at the locked position; and a second pressed portion being far from the positioning frame than the second guiding plane, the second pressed portion engaging with the second resisting portion when the linkage member is oriented at the locked position.
 11. The adjustable exercise bicycle of claim 10, wherein the first guiding plane and the second guiding plane are beveled.
 12. The adjustable exercise bicycle of claim 10, wherein the first guiding plane engages with the first hole wall of one of the positioning holes and the second guiding plane engages with the second wall hole of another positioning hole which is near the foregoing positioning hole when the linkage member is oriented at the locked position.
 13. The adjustable exercise bicycle of claim 10, wherein the second guiding plane is face to the first guiding plane.
 14. The adjustable exercise bicycle of claim 10, wherein the second guiding plane is opposite to the first guiding plane. 